diff options
Diffstat (limited to 'security/selinux/ss/mls.c')
| -rw-r--r-- | security/selinux/ss/mls.c | 71 |
1 files changed, 48 insertions, 23 deletions
diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c index 756036bcc24..d4c32c39ccc 100644 --- a/security/selinux/ss/mls.c +++ b/security/selinux/ss/mls.c @@ -15,6 +15,7 @@ #include <linux/slab.h> #include <linux/string.h> #include <linux/errno.h> +#include "sidtab.h" #include "mls.h" #include "policydb.h" #include "services.h" @@ -208,6 +209,26 @@ int mls_context_isvalid(struct policydb *p, struct context *c) } /* + * Copies the MLS range from `src' into `dst'. + */ +static inline int mls_copy_context(struct context *dst, + struct context *src) +{ + int l, rc = 0; + + /* Copy the MLS range from the source context */ + for (l = 0; l < 2; l++) { + dst->range.level[l].sens = src->range.level[l].sens; + rc = ebitmap_cpy(&dst->range.level[l].cat, + &src->range.level[l].cat); + if (rc) + break; + } + + return rc; +} + +/* * Set the MLS fields in the security context structure * `context' based on the string representation in * the string `*scontext'. Update `*scontext' to @@ -216,10 +237,20 @@ int mls_context_isvalid(struct policydb *p, struct context *c) * * This function modifies the string in place, inserting * NULL characters to terminate the MLS fields. + * + * If a def_sid is provided and no MLS field is present, + * copy the MLS field of the associated default context. + * Used for upgraded to MLS systems where objects may lack + * MLS fields. + * + * Policy read-lock must be held for sidtab lookup. + * */ int mls_context_to_sid(char oldc, char **scontext, - struct context *context) + struct context *context, + struct sidtab *s, + u32 def_sid) { char delim; @@ -231,9 +262,23 @@ int mls_context_to_sid(char oldc, if (!selinux_mls_enabled) return 0; - /* No MLS component to the security context. */ - if (!oldc) + /* + * No MLS component to the security context, try and map to + * default if provided. + */ + if (!oldc) { + struct context *defcon; + + if (def_sid == SECSID_NULL) + goto out; + + defcon = sidtab_search(s, def_sid); + if (!defcon) + goto out; + + rc = mls_copy_context(context, defcon); goto out; + } /* Extract low sensitivity. */ scontextp = p = *scontext; @@ -334,26 +379,6 @@ out: } /* - * Copies the MLS range from `src' into `dst'. - */ -static inline int mls_copy_context(struct context *dst, - struct context *src) -{ - int l, rc = 0; - - /* Copy the MLS range from the source context */ - for (l = 0; l < 2; l++) { - dst->range.level[l].sens = src->range.level[l].sens; - rc = ebitmap_cpy(&dst->range.level[l].cat, - &src->range.level[l].cat); - if (rc) - break; - } - - return rc; -} - -/* * Copies the effective MLS range from `src' into `dst'. */ static inline int mls_scopy_context(struct context *dst, |